before this change, we rely on the default-generated fmt::formatter
created from operator<<, but fmt v10 dropped the default-generated
formatter.
in this change, we include `fmt/ranges.h` and/or `fmt/std.h`
for formatting the container types, like vector, map
optional and variant using {fmt} instead of the homebrew
formatter based on operator<<.
with this change, the changes adding fmt::formatter and
the changes using ostream formatter explicitly, we are
allowed to drop `FMT_DEPRECATED_OSTREAM` macro.
Refs scylladb#13245
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Fixes some typos as found by codespell run on the code.
In this commit, I was hoping to fix only comments, not user-visible alerts, output, etc.
Follow-up commits will take care of them.
Refs: https://github.com/scylladb/scylladb/issues/16255
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
To allow paging for requests that don't go through storage-proxy
directly. By default, there is no override and the code falls-back to
directly invoking storage_proxy::query() as before.
The code for compare_endpoints originates at the dawn of time (bc034aeaec)
and is called on the fast path from storage_proxy via `sort_by_proximity`.
This series considerably reduces the function's footprint by:
1. carefully coding the many comparisons in the function so to reduce the number of conditional banches (apparently the compiler isn't doing a good enough job at optimizing it in this case)
2. avoid sstring copy in topology::get_{datacenter,rack}
Closes#12761
* github.com:scylladb/scylladb:
topology: optimize compare_endpoints
to_string: add print operators for std::{weak,partial}_ordering
utils: to_sstring: deinline std::strong_ordering print operator
move to_string.hh to utils/
test: network_topology: add test_topology_compare_endpoints
these warnings are found by Clang-17 after removing
`-Wno-unused-lambda-capture` and '-Wno-unused-variable' from
the list of disabled warnings in `configure.py`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Schema related files are moved there. This excludes schema files that
also interact with mutations, because the mutation module depends on
the schema. Those files will have to go into a separate module.
Closes#12858
Move mutation-related files to a new mutation/ directory. The names
are kept in the global namespace to reduce churn; the names are
unambiguous in any case.
mutation_reader remains in the readers/ module.
mutation_partition_v2.cc was missing from CMakeLists.txt; it's added in this
patch.
This is a step forward towards librarization or modularization of the
source base.
Closes#12788
Now that we don't accept cql protocol version 1 or 2, we can
drop cql_serialization format everywhere, except when in the IDL
(since it's part of the inter-node protocol).
A few functions had duplicate versions, one with and one without
a cql_serialization_format parameter. They are deduplicated.
Care is taken that `partition_slice`, which communicates
the cql_serialization_format across nodes, still presents
a valid cql_serialization_format to other nodes when
transmitting itself and rejects protocol 1 and 2 serialization\
format when receiving. The IDL is unchanged.
One test checking the 16-bit serialization format is removed.
This fixes a long standing bug related to handling of non-full
clustering keys, issue #1446.
after_key() was creating a position which is after all keys prefixed
by a non-full key, rather than a position which is right after that
key.
This will issue will be caught by cql_query_test::test_compact_storage
in debug mode when mutation_partition_v2 merging starts inserting
sentinels at position after_key() on preemption.
It probably already causes problems for such keys.
The pager currently assumes that an empty pages means the query is
exhausted. Lift this assumption, as we will soon have empty short
pages.
Also, paging using filtering also needs to use the replica-provided
last-position when the page is empty.
Add include statements to satisfy dependencies.
Delete, now unneeded, include directives from the upper level
source files.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
query_result was the wrong place to put last position into. It is only
included in data-responses, but not on digest-responses. If we want to
support empty pages from replicas, both data and digest responses have
to include the last position. So hoist up the last position to the
parent structure: query::result. This is a breaking change inter-node
ABI wise, but it is fine: the current code wasn't released yet.
Closes#11072
Currently, we use the last row in the query result set as the position where the query is continued from on the next page. Since only live rows make it into query result set, this mandates the query to be stopped on a live row on the replica, lest any dead rows or tombstones processed after the live rows, would have to be re-processed on the next page (and the saved reader would have to be thrown away due to position mismatch). This requirement of having to stop on a live row is problematic with datasets which have lots of dead rows or tombstones, especially if these form a prefix. In the extreme case, a query can time out before it can process a single live row and the data-set becomes effectively unreadable until compaction gets rid of the tombstones.
This series prepares the way for the solution: it allows the replica to determine what position the query should continue from on the next page. This position can be that of a dead row, if the query stopped on a dead row. For now, the replica supplies the same position that would have been obtained with looking at the last row in the result set, this series merely introduces the infrastructure for transferring a position together with the query result, and it prepares the paging logic to make use of this position. If the coordinator is not prepared for the new field, it will simply fall-back to the old way of looking at the last row in the result set. As I said for now this is still the same as the content of the new field so there is no problem in mixed clusters.
Refs: https://github.com/scylladb/scylla/issues/3672
Refs: https://github.com/scylladb/scylla/issues/7689
Refs: https://github.com/scylladb/scylla/issues/7933
Tests: manual upgrade test.
I wrote a data set with:
```
./scylla-bench -mode=write -workload=sequential -replication-factor=3 -nodes 127.0.0.1,127.0.0.2,127.0.0.3 -clustering-row-count=10000 -clustering-row-size=8096 -partition-count=1000
```
This creates large, 80MB partitions, which should fill many pages if read in full. Then I started a read workload:
```
./scylla-bench -mode=read -workload=uniform -replication-factor=3 -nodes 127.0.0.1,127.0.0.2,127.0.0.3 -clustering-row-count=10000 -duration=10m -rows-per-request=9000 -page-size=100
```
I confirmed that paging is happening as expected, then upgraded the nodes one-by-one to this PR (while the read-load was ongoing). I observed no read errors or any other errors in the logs.
Closes#10829
* github.com:scylladb/scylla:
query: have replica provide the last position
idl/query: add last_position to query_result
mutlishard_mutation_query: propagate compaction state to result builder
multishard_mutation_query: defer creating result builder until needed
querier: use full_position instead of ad-hoc struct
querier: rely on compactor for position tracking
mutation_compactor: add current_full_position() convenience accessor
mutation_compactor: s/_last_clustering_pos/_last_pos/
mutation_compactor: add state accessor to compact_mutation
introduce full_position
idl: move position_in_partition into own header
service/paging: use position_in_partition instead of clustering_key for last row
alternator/serialization: extract value object parsing logic
service/pagers/query_pagers.cc: fix indentation
position_in_partition: add to_string(partition_region) and parse_partition_region()
mutation_fragment.hh: move operator<<(partition_region) to position_in_partition.hh
Use the recently introduced query-result facility to have the replica
set the position where the query should continue from. For now this is
the same as what the implicit position would have been previously (last
row in result), but it opens up the possibility to stop the query at a
dead row.
The former allows for expressing more positions, like a position
before/after a clustering key. This practically enables the coordinator
side paging logic, for a query to be stopped at a tombstone (which can
have said positions).
After fcb8d040 ("treewide: use Software Package Data Exchange
(SPDX) license identifiers"), many dual-licensed files were
left with empty comments on top. Remove them to avoid visual
noise.
Closes#10562
Recently, coordinator_result was introduced as an alternative for
exceptions. It was placed in the main "exceptions/exceptions.hh" header,
which virtually every single source file in Scylla includes.
But unfortunately, it brings in some heavy header files and templates,
leading to a lot of wasted build time - ClangBuildAnalyzer measured that
we include exceptions.hh in 323 source files, taking almost two seconds
each on average.
In this patch, we split the coordinator_result feature into a separate
header file, "exceptions/coordinator_result", and only the few places
which need it include the header file. Unfortunately, some of these
few places are themselves header, so the new header file ends up being
included in 100 source files - but 100 is still much less than 323 and
perhaps we can reduce this number 100 later.
After this patch, the total Scylla object-file size is reduced by 6.5%
(the object size is a proxy for build time, which I didn't directly
measure). ClangBuildAnalyzer reports that now each of the 323 includes
of exceptions.hh only takes 80ms, coordinator_result.hh is only included
100 times, and virtually all the cost to include it comes from Boost's
result.hh (400ms per inclusion).
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20220228204323.1427012-1-nyh@scylladb.com>
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
There are few places that need storage proxy and that use
global method to acheive it. Since previous patch there's
a pager local non-null pointer.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Pagers are created by alternator and select statement, both
have the proxy reference at hands. Next, the pager's unique_ptr
is put on the lambda of its fetch_page() continuation and thus
it survives the fetch_page execution and then gets destroyed.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Query pager was reusing query_uuid only when it had no local state (no
_last_pkey), so querier cache was not used when paging locally.
This bug affects performance of aggregate queries like count(*).
Fixes#9127
Message-Id: <20210803003941.175099-1-tgrabiec@scylladb.com>
storage_proxy.hh is huge and includes many headers itself, so
remove its inclusions from headers and re-add smaller headers
where needed (and storage_proxy.hh itself in source files that
need it).
Ref #1.
Nested classes cannot be forward declared, and
storage_proxy::coordinator_query_result is used in pagers, where
we'd like to forward-declare it. Unnest it and introduce an alias
for compatibility.
As #1449 notes, trichotomic comparators returning int are dangerous as they
can be mistaken for less comparators. This series converts dht::ring_position
and dht::decorated_key, as well as a few closely related downstream types, to
return std::strong_ordering.
Closes#8225
* github.com:scylladb/scylla:
dht: ring_position, decorated_key: convert tri_comparators to std::strong_ordering
pager: rephrase misleading comparison check
test: total_order_checks: prepare for std::strong_ordering
test: mutation_test: prepare merge_container for std::strong_ordering
intrusive_array: prepare for std::strong_ordering
utils: collection-concepts: prepare for std::strong_ordering
We check !result_of_tri_compare, which makes it look like we're
checking a boolean predicate, whereas we're really checking for
equality. Change to result_of_tri_compare == 0, which is less likely
to be confusing, and is also compatible with std::strong_ordering.
Before updating the _last_[cp]key (for subsequent .fetch_page())
the pager checks is 'if the pager is not exhausted OR the result
has data'.
The check seems broken: if the pager is not exhausted, but the
result is empty the call for keys will unconditionally try to
reference the last element from empty vector. The not exhausted
condition for empty result can happen if the short_read is set,
which, in turn, unconditionally happens upon meeting partition
end when visiting the partition with result builder.
The correct check should be 'if the pager is not exhausted AND
the result has data': the _last_[pc]key-s should be taken for
continuation (not exhausted), but can be taken if the result is
not empty (has data).
fixes: #7263
tests: unit(dev), but tests don't trigger this corner case
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Message-Id: <20200921124329.21209-1-xemul@scylladb.com>
Currently, we cannot select more than 2^32 rows from a table because we are limited by types of
variables containing the numbers of rows. This patch changes these types and sets new limits.
The new limits take effect while selecting all rows from a table - custom limits of rows in a result
stay the same (2^32-1).
In classes which are being serialized and used in messaging, in order to be able to process queries
originating from older nodes, the top 32 bits of new integers are optional and stay at the end
of the class - if they're absent we assume they equal 0.
The backward compatibility was tested by querying an older node for a paged selection, using the
received paging_state with the same select statement on an upgraded node, and comparing the returned
rows with the result generated for the same query by the older node, additionally checking if the
paging_state returned by the upgraded node contained new fields with correct values. Also verified
if the older node simply ignores the top 32 bits of the remaining rows number when handling a query
with a paging_state originating from an upgraded node by generating and sending such a query to
an older node and checking the paging_state in the reply(using python driver).
Fixes#5101.
This field will replace max size which is currently passed once per
established rpc connection via the CLIENT_ID verb and stored as an
auxiliary value on the client_info. For now it is unused, but we update
all sites creating a read command to pass the correct value to it. In the
next patch we will phase out the old max size and use this field to pass
max size on each verb instead.
All callers should set this already before passing the slice to the
pager, however not all actually do (e.g.
`cql3::indexed_table_select_statement::read_posting_list()`). Instead of
auditing each call site, just make sure this is set in the pager
itself. If someone is creating a pager we can be sure they mean to use
paging.
Pager belongs to a different layer than CQL and thus should not be
coupled with CQL stats - if any different frontends want to use paging,
they shouldn't be forced to instantiate CQL stats at all.
Same goes with CQL restrictions, but that will require much bigger
refactoring, so is left for later.
Message-Id: <5585eb470949e3457334ffd6dba80742abf3a631.1592902295.git.sarna@scylladb.com>
Seastar recently lost support for the experimental Concepts Technical
Specification (TS) and gained support for C++20 concepts. Re-enable
concepts in Scylla by updating our use of concepts to the C++20
standard.
This change:
- peels off uses of the GCC6_CONCEPT macro
- removes inclusions of <seastar/gcc6-concepts.hh>
- replaces function-style concepts (no longer supported) with
equation-style concepts
- semicolons added and removed as needed
- deprecated std::is_pod replaced by recommended replacement
- updates return type constraints to use concepts instead of
type names (either std::same_as or std::convertible_to, with
std::same_as chosen when possible)
No attempt is made to improve the concepts; this is a specification
update only.
Message-Id: <20200531110254.2555854-1-avi@scylladb.com>
The constructor of `read_command` is used both by IDL and clients in the
code. However, this constructor has a parameter that is not used by IDL:
`read_timestamp`. This requires that this parameter is the very last in
the list and that new parameters that are used by IDL are added before
it. One such new parameter was `bool is_first_page`. Adding this
parameter right before the read timestamp one created a situation where
the last parameter (read_timestamp) implicitly converts to the one
before it (is_first_page). This means that some call sites passing
`read_timestamp` were now silently converting this to `is_first_page`,
effectively dropping the timestamp.
This patch aims to rectify this, while also avoiding similar accidents
in the future, by making `is_first_page` a `bool_class` which doesn't
have any implicit convertions defined. This change does not break the
ABI as `bool_class` is also sent as a `bool` on the wire.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Tests: unit(dev)
Message-Id: <20200422073657.87241-1-bdenes@scylladb.com>
